Slitting machine



SLITTING MACHINE Filed April 15, 1946 H. E. VAN DERl-[QEF EI'ALLNVENTORS HENRYE. VAN DERHOEF ATTORNEYS IKALCOLM P. DAVIS Sept. 7, 1948.

Patented Sept. 7, 1948 UNITED STATES PATENT OFFICE SLITTING MACHINEHenry E. Van Derhoef, Rochester, N. Y., and Malcolm P. Davis, Sarasota,Fla., assignors to Eastman Kodak Company, Rochester, N. Y., acorporation of New Jersey Application April 15, 1946, Serial No. 662,172

, l This invention relates to machines particularly designed forproducing accurately-formed slits in strip material, such as cellulosenitrate, cellulose acetate, or the like. One object of our invention isto provide a machine for slitting strip material in which the slittingknives can be readily held in operative relationship. Another object ofour invention is to provide a machine of the class described, in whichthe moving parts, insofar as possible, are enclosed, and in which thelubricating means is enclosed to prevent soiling the sheet to be slit.Another object of our invention is to provide a means for holding theslitting knives in operative relationship which entirely omits the usualuse ofspringsior this purpose. A still further object of our inventionis to provide a slitting machine in which the position of the slittingknives relative to the strip material can be easily and accuratelyadjusted to different positions relative to the width of thesheet. Astill further object of our invention is to provide a slitting mechanismwhich can be readily set up and taken down with a minimum of difficultyin accurately aligning the parts of the machine, in setting up themachine for operation, and other objects will appear from the followingspecification, the novel features being particularly pointed out in theclaims at the end thereof.

This slitting machine may be considered an improvement over the slittingmachine construction shown in Patent 2,238,481, granted April 15, 1941,in the name of Henry E. Van Derhoei.

Coming now to the drawings wherein like reference characters denote likeparts throughout:

Fig. 1 is a fragmentary front elevation and part section of a typicalembodiment of a slitting machine constructed in accordance with andembodying a preferred form of our invention;

Fig. 2 is a fragmentary side elevation of the machine shown in Fig. 1with certain parts omitted for the sake of clearness;

Fig. 3 is an enlarged detailed section showing the relationship of thecircular slitting knives when the machine is set up for operation;

Fig. 4 is a fragmentary detailed section of the gear drive for theslitting knives; and

Fig. 5 is an enlarged fragmentary sectional view showing th relationshipof th slitting knives and their relation to a sheet being slit.

It has been comparatively difficult to provide machines which willsatisfactorily slit long strips of material with a high degree ofaccuracy. particularly where the material may be of a cellulose acetateor cellulose nitrate sheeting. Many materials, and particularly suchacetatesheet- 4 Claims. (01. 164-61) ings, are liable to haveundulations, or wrinkles, in the material as it passes through itsnormal path, so that it the material is slit in this wrinkled condition,it is impossible to obtain accurate dimensions between slits. Moreover,there is quite a varietyof thicknesses of material which may requiresomewhat different types of machines for producing the desirable clean,accurate slits in the material. The embodiment of our machine, which weare about to describe, has been particularly designed for slittingcellulose acetate, or'nitrate, sheeting of from perhaps .002 to .15inches in thickness, although, obviously, such a machine is also usefulfor other types and thicknesses of material. The parts of our machinehave been particularly designed to exclude all dust, oil; dirt,- andforeign matter from the sheetingwherever possible, and to avoid anylubricating materials from coming in contact with the final sheet. Wheresuch material is to be used for photographic film, it is particularlynecessary to avoid contacting the sheet with any foreign matter, and toprovide a construction in which the knives themselves must be arrangedto prevent the knives from producing even minute quantities of metaldust from the knives during the slitting operation. This may occur fromknives which to the naked eye appear to be finely ground, but whichunder microscopes appear to be somewhat rough or irregular. Suchirregularities may be removed by honing.

- Our invention comprises broadly providing a slitting machine inwhichthere is a support carrying a horizontal trackon which one or morecarriages bearing slitting knives are slidably mounted and onwhich theymay be accurately adjusted by means of a hand wheel to the exactposition required. The sheet material to be slit isledaround one or morerollers having contact through a considerable angle, such as 170 or 180degrees, and since this contact causes the material to produce a partcylinder as it passes about the supporting rollers,fanyundulations orwrinkles in the material are smoothed out, and the 3 which, as shown inFig. 2, is dovetailed in cross section or end elevation. On this trackare mounted one or more carriages 3 which are preferably similar inconstruction, although they may be made both right and left-handed, asshown in Fig. 1. The carriage 3 is provided with brackets 4 whichrevolvabl support a .roller-Eas by means of ball bearings 6, these ballbearings being carried by a shaft 1, a reduced end 8 of which may carrya helical gear 9. The roller 5 may turn freely upon the shaft 1 andreceives its movement from the movement of the strip material S whichpasses through a path which may be defined by the rollers [0, 5, 1],l2,- 113,-and The strip material S is driven at a-prede'termined numberof feet per second by suitable rollers which are not shown in thepresent drawing, 1- though any roller frictionally engaging the sheetmaterial S could be used for this purpose. roller 5 therefore turns atthe same number of feet per minute as the strip material -S -because theroller is turned-thereby.

The shaft .8 carries one-cutting knife l 5 so that this knife willbedriventhrough the gear 9-at a rate of speed which is preferablyisl-ightlysin excess to the speed (in i-eetper minute) of the sheetmaterial S passing around the roller-5. The circular knife I 5 isfixedly mounted withrespect to the carriaget because precautions'havebeen taken to prevent .end play in the shaft 'I...8. However, asecond .stub shaft 16 is .preferably provided with slight end playwas,for instance, of an inch, sothat the cutting knife .11 may be held intocontact with the icutting'knif-e because of the thrust on shaft i6exerted by .a

helical gear I8 meshing withna helical gear 3. The angle of thetee'thofthese :helical .gearsis selected to exert thedesired pressure:on the. knife i'l against the knife t5 and :by increasing-.athe angle ofthe teeth, the pressure may beincreased, and by decreasing the angle ofthe'teeth, the pressure may be decreased. .IWBIhBVBAfOIlIid' that. atooth angle ofapproximately20 degrees fromthe shaft it gives very:desirable results with the machine shown inythe drawings.

As indicated in Fig.'5,.the knivesglfi and ;lt1have cutting edges 20 and2| which are substantially at right angles to the peripheries 12:2 and23 .of these knives. Theedges are undercut, as shown, and in operationthere is only a slight overlap between these edges so that .a cleancut-may be made through the sheet material, while the peripheries 22 and23 are. at least. partially supporting the sheet material Sbeing slit.

In the present -instanoe,.athe machme is setup to slit the two edges .ofthe strip material ;S;; the edges E to be removed being ledqfromtheslitting knives i5 and I] over rollers 25 2 6 ,;and thence to asuitable take-up mechanism, not shown. The p s t machin :is a sokprvided with two carriages 3, one being rightehandand the other beingleft-hand, the set-up being intended ,to out off the two edges E of asheets, leaving the remaining part out {accurately to the desired-widthdimension.

In order to drive thefhelicaligears L8 and 9, there is a third helicalgear 21 which is, mounted to turn with, but slideon. .a shaft 28. Thisshaft is carried by suitable bearings 29 onthe support I in which ballbearing s 3ll-are preferably pro.- vided and one end ofthe shaft-;2 8;isprovided a gear 3| which derives its power through a pine ion 32 and amain drive gear 33 1ca11-riedJoy" a shaft 34. g g

Th s a 5- 8 a d flare enc os s-en a hous- The 4 ing 35 which confinesthe lubricating means inside of the housing, leaving a clean exterior.

Each carriage 3 is mounted to slide on the track 2 and in order toadjust the carriage accurately to the proper position, a screw 36 isprovided; this screw being pinned at 31 to the carriage and carrying awormwheel 38 meshing with a worm 39 so that by turning the handwheel 4B,the carriage 3 may be moved along the track 2.

It should be noticed that the gear 18 is slightly smaller than the gear9, the reason for this being that it is desirable to have one cuttingknife 11 tained by 1 having a difference of one or more "teethinthe'gea'r s 9 and I8 and as a result, the

two'knives l5 and vIl, turning together, do not tend to score each otherby one part of one knife always striking another part of the otherknife.

Since there is a constantly changing relationship between the :knives,the edges 20and 21 (which are the cutting edges) are preserved againstundue wear. We have found it desirable to both grind and hone thecutting edges 20 and.2l and we have found that with such .edges, theknives will wear an extremely long time without .deteriorationzandproduce clean and accurate'slits in the material. This, in part, due, nodoubt, to the fact that there is. an ever-present, even, endwise thruston the shaft I6, so that. knife 11 bears against the knife it with asubstantially constant and even pressure due to the angle. of the teethof'the gears 52 and Hi. It should :be noticed that the periphery .22lies in substantial alignmentwith the periphery .of the roller Sand maybe considered to form a continuation vof the supporting surface .of theroller 5 on which the strip material Slies as the knives slitthe.;ma.-terialto free the unwanted edge E therefrom.

The position and the number .of the carriages 3 will dependx-of. course,on the number of strips into which it is desirable to slit .a singlesheet. The strip material S, in passing around the rollers 5, willreadily bridge'the .gap between the ends of these rollers because itwill be remembered that in this position the material is in the form .ofa part cylinder in which the material is comparatively rigid and whichsupports-an even and smooth arch so that the total .distancebetween anypair ofslitting knives can be accurately determined .and maintained. 7

Our present construction particularly avoids the use .of springs which,under many instances, may work satisfactorily but which have thedisadvantage of being difiicult to arrange-so that perfectly .even.axial pressure is exerted on the knives because it .is difficult first,to cut the ends of the spring in such .aumanner that they .will exerteven pressure and, second, it is difficult to prevent lubrication fromfailing because where a machine is set with a constant spring tensionfor use over a long period of time, movement of the spring may beretarded by thickened lubricant, tending to prevent free movement of thespring and consequently uneven pressure upon the cutting knives. In ourpresent slittingmachine, the pressure is obtained by the constantmeshing of the .an gularly-positioned helical gear teeth, so that thereis always an end thrust on theshaftltli in the direction shown by thearrow A. Thedirection and slope of the teeth .of the helical gears is,alwaysso arranged and selected that the end thrust will cause themovable cuttingknife H to lie in firm contact with the-.relatively-fixedcutting knife l5 so that a cleanlysheared edge will result.

We claim:

1. A slitting machine comprising, in combination, a support, a trackcarried thereby, a carriage movably mounted on the track, a rollercarried by the carriage, a shaft, a slitting knife positioned coaxiallyof the roller and on the shaft, a stub shaft carried by the carriage, aslitting knife carried thereby, there being axial play in the stubshaft, helical meshing gears positioned one on the shaft coaxially withthe roller and the other on the stub shaft to exert an end thrust onsaid stub shaft to operably engage the knife on the stub shaft with theknife coaxially mounted with respect to the roller.

2. A slitting machine comprising, in combination, a support, a trackcarried thereby, a carriage movably mounted on the track, a rollercarried by the carriage, a shaft, 9, slitting knife positionedcoaxial-1y of the roller and on the shaft, said roller being mounted onsaid shaft for relative rotation thereto, a stub shaft carried by thecarriage, a slitting knife carried thereby, there being axial play inthe stub shaft, helical meshing gears positioned one on the shaftcoaxially with the roller and the other on the stub shaft to exert anend thrust on said stub shaft to operably engage the knife on the stubshaft with the knife coaxially mounted with respect to the roller, meansfor leading strip material about the roller, the helical gear means fordriving the slitting knives may thus move said knives at a peripheralspeed higher than the predetermined speed of the strip material passingover said roller.

3. A slitting machine comprising, in combination, a support, a trackcarried thereby, a carriage movably mounted on the track, means formoving the carriage along the track to position the carriage thereon, aroller carried by the carriage, a shaft, a slitting knife positionedcoaxial'ly of the roller and on the shaft, a stub shaft carried by thecarriage, a slitting knife carried thereby, there being axial play inthe stub shaft, helical meshing gears positioned one on the shaftcoaxially with the roller and the other on the stub shaft to exert anend thrust on said stub shaft to operably engage the knife on the stubshaft with the knife coaxially mounted with respect to the roller.

4. A slitting machine as defined in claim 1 characterized by theslitting knife, arranged coaxia-lly of the roller, and the roller bothbeing carried by a shaft parallel to the track carried. by the carriage,a shaft passing through the carriage, a gear on said last-mentionedshaft for driving the helical gears connected to the slitting knives,said shaft passing through the carriage and being carried in bearings onthe support.

HENRY E. VAN DERHOEF. MALCOLM P. DAVIS.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 586,808 Dittman July 20, 18971,024,409 Luther Apr. 23, 1912 1,534,257 Brogan Apr. 21, 1925 1,678,458Biggert July 24, 1928 1,774,549 Finn Sept. 2, 1930 1,807,835 Finn June2, 1931

